This interactive graphic, showing how world records in olympic events have changed over time, is pretty damn cool. The improvement in the discus is particularly stunning.
While part of this has to do with improved training and technology, these are just part of a larger trend of tapping deeper into the human potential. The people we were a century ago were a shadow of what we are now — well-fed people with all our teeth, marbles and bones who can live functionally into our 80′s. Vaccines and the reduction of childhood disease, in particular, have created an explosion in human healthy, lifetime and potential.
I do think we are reaching the limits this side of genetic engineering. Watch how the records asymptote. I just hope the same isn’t true of our progress in science and technology.